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- // See http://www.boost.org/libs/any for Documentation.
- #ifndef BOOST_ANY_INCLUDED
- #define BOOST_ANY_INCLUDED
- // what: variant type boost::any
- // who: contributed by Kevlin Henney,
- // with features contributed and bugs found by
- // Ed Brey, Mark Rodgers, Peter Dimov, and James Curran
- // when: July 2001
- // where: tested with BCC 5.5, MSVC 6.0, and g++ 2.95
- #include <algorithm>
- #include <typeinfo>
- #include "boost/config.hpp"
- #include <boost/type_traits/remove_reference.hpp>
- #include <boost/type_traits/is_reference.hpp>
- #include <boost/throw_exception.hpp>
- #include <boost/static_assert.hpp>
- // See boost/python/type_id.hpp
- // TODO: add BOOST_TYPEID_COMPARE_BY_NAME to config.hpp
- # if (defined(__GNUC__) && __GNUC__ >= 3) \
- || defined(_AIX) \
- || ( defined(__sgi) && defined(__host_mips)) \
- || (defined(__hpux) && defined(__HP_aCC)) \
- || (defined(linux) && defined(__INTEL_COMPILER) && defined(__ICC))
- # define BOOST_AUX_ANY_TYPE_ID_NAME
- #include <cstring>
- # endif
- namespace boost
- {
- class any
- {
- public: // structors
- any()
- : content(0)
- {
- }
- template<typename ValueType>
- any(const ValueType & value)
- : content(new holder<ValueType>(value))
- {
- }
- any(const any & other)
- : content(other.content ? other.content->clone() : 0)
- {
- }
- ~any()
- {
- delete content;
- }
- public: // modifiers
- any & swap(any & rhs)
- {
- std::swap(content, rhs.content);
- return *this;
- }
- template<typename ValueType>
- any & operator=(const ValueType & rhs)
- {
- any(rhs).swap(*this);
- return *this;
- }
- any & operator=(any rhs)
- {
- rhs.swap(*this);
- return *this;
- }
- public: // queries
- bool empty() const
- {
- return !content;
- }
- const std::type_info & type() const
- {
- return content ? content->type() : typeid(void);
- }
- #ifndef BOOST_NO_MEMBER_TEMPLATE_FRIENDS
- private: // types
- #else
- public: // types (public so any_cast can be non-friend)
- #endif
- class placeholder
- {
- public: // structors
- virtual ~placeholder()
- {
- }
- public: // queries
- virtual const std::type_info & type() const = 0;
- virtual placeholder * clone() const = 0;
- };
- template<typename ValueType>
- class holder : public placeholder
- {
- public: // structors
- holder(const ValueType & value)
- : held(value)
- {
- }
- public: // queries
- virtual const std::type_info & type() const
- {
- return typeid(ValueType);
- }
- virtual placeholder * clone() const
- {
- return new holder(held);
- }
- public: // representation
- ValueType held;
- private: // intentionally left unimplemented
- holder & operator=(const holder &);
- };
- #ifndef BOOST_NO_MEMBER_TEMPLATE_FRIENDS
- private: // representation
- template<typename ValueType>
- friend ValueType * any_cast(any *);
- template<typename ValueType>
- friend ValueType * unsafe_any_cast(any *);
- #else
- public: // representation (public so any_cast can be non-friend)
- #endif
- placeholder * content;
- };
- class bad_any_cast : public std::bad_cast
- {
- public:
- virtual const char * what() const throw()
- {
- return "boost::bad_any_cast: "
- "failed conversion using boost::any_cast";
- }
- };
- template<typename ValueType>
- ValueType * any_cast(any * operand)
- {
- return operand &&
- #ifdef BOOST_AUX_ANY_TYPE_ID_NAME
- std::strcmp(operand->type().name(), typeid(ValueType).name()) == 0
- #else
- operand->type() == typeid(ValueType)
- #endif
- ? &static_cast<any::holder<ValueType> *>(operand->content)->held
- : 0;
- }
- template<typename ValueType>
- inline const ValueType * any_cast(const any * operand)
- {
- return any_cast<ValueType>(const_cast<any *>(operand));
- }
- template<typename ValueType>
- ValueType any_cast(any & operand)
- {
- typedef BOOST_DEDUCED_TYPENAME remove_reference<ValueType>::type nonref;
- #ifdef BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION
- // If 'nonref' is still reference type, it means the user has not
- // specialized 'remove_reference'.
- // Please use BOOST_BROKEN_COMPILER_TYPE_TRAITS_SPECIALIZATION macro
- // to generate specialization of remove_reference for your class
- // See type traits library documentation for details
- BOOST_STATIC_ASSERT(!is_reference<nonref>::value);
- #endif
- nonref * result = any_cast<nonref>(&operand);
- if(!result)
- boost::throw_exception(bad_any_cast());
- return *result;
- }
- template<typename ValueType>
- inline ValueType any_cast(const any & operand)
- {
- typedef BOOST_DEDUCED_TYPENAME remove_reference<ValueType>::type nonref;
- #ifdef BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION
- // The comment in the above version of 'any_cast' explains when this
- // assert is fired and what to do.
- BOOST_STATIC_ASSERT(!is_reference<nonref>::value);
- #endif
- return any_cast<const nonref &>(const_cast<any &>(operand));
- }
- // Note: The "unsafe" versions of any_cast are not part of the
- // public interface and may be removed at any time. They are
- // required where we know what type is stored in the any and can't
- // use typeid() comparison, e.g., when our types may travel across
- // different shared libraries.
- template<typename ValueType>
- inline ValueType * unsafe_any_cast(any * operand)
- {
- return &static_cast<any::holder<ValueType> *>(operand->content)->held;
- }
- template<typename ValueType>
- inline const ValueType * unsafe_any_cast(const any * operand)
- {
- return unsafe_any_cast<ValueType>(const_cast<any *>(operand));
- }
- }
- // Copyright Kevlin Henney, 2000, 2001, 2002. All rights reserved.
- //
- // Distributed under the Boost Software License, Version 1.0. (See
- // accompanying file LICENSE_1_0.txt or copy at
- // http://www.boost.org/LICENSE_1_0.txt)
- #endif
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